The present invention relates to a method and an apparatus for lubricating a piston type compressor and more particularly to a lubricating structure in a piston type compressor for guiding lubricant to a drive mechanism that reciprocates a piston.
Unexamined Japanese Patent Publication No. 6-101641 discloses a compressor of such type. The compressor is a double-headed piston type swash plate compressor. A cylindrical passage that has a spiral groove is formed in a drive shaft of the compressor. The cylindrical passage opens in a low pressure chamber or a suction pressure region at its first end and extends toward its second end. A lubricating hole is formed in a circumferential surface of the drive shaft in a radial direction of the drive shaft for guiding lubricant to thrust bearings that rotatably support a swash plate. As the drive shaft rotates, the lubricant is transferred along the spiral groove toward the second end. Subsequently, the lubricant is fed to the thrust bearings through the lubricating hole and flows into a crank chamber. Thus, the lubricant lubricates a sliding surface between the swash plate and a shoe, a sliding surface between the shoe and the piston, and a sliding surface of the thrust bearing in the drive mechanism that reciprocates the piston.
An unwanted feature is that the above disclosed lubricating structure does not sufficiently lubricates a required lubricating portion. There is a need for a lubricating structure that improves lubrication on the drive mechanism in comparison to the above disclosed lubricating structure.